Transcript Blood Groups & Blood Transfusion

Blood Groups & Blood Transfusion
HMIM BLOCK 224
Dr. Shaikh Mujeeb Ahmed
Assistant Professor
AlMaarefa College
Objectives
Different types of Blood groups blood group
system
Explain blood typing and how it is used to
avoid adverse reactions following blood
transfusions.
 Describe how blood reactions may occur
between fetal and maternal tissues.
Blood Groups and Transfusions
• In the year 1900, identification of the ABO
blood antigen gene explained the observed
blood type incompatibilities by Karl
Landsteiner
• Today there are 31 different genes known to
contribute to the surface features of RBCs
determining compatibility between blood
types
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Blood Group Systems
• Major systems
– ABO
– Rhesus system(Rh)
• Minor
– MN
–P
– Familial blood groups
Importance of Blood Groups
• Transfusion of blood
• Association with disease
• Duodenal ulcers are more common in group O than in A
or B
• Tumors of salivary glands, stomach and pancreas are
more common in group A than in group O individuals.
Antigens and Antibodies
• Terms to become familiar with:
• Agglutination – clumping of red blood
cells in response to a reaction between an
antibody and an antigen
• Antigens – a chemical that stimulates cells
to produce antibodies
• Antibodies – a protein that reacts against
a specific antigen
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Red blood cell
Red blood cell
Anti-B antibody
Antigen A
Anti-A antibody
Antigen B
Type B blood
Type A blood
Red blood cell
Anti-A antibody
Anti-B antibody
Antigen A
Antigen B
Red blood cell
Type AB blood
Type O blood
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Antigen A
Anti-B antibody
(a)
(c)
Agglutinated red
blood cells
Red blood cell
Anti-A antibody
(b)
(d)
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ABO Blood Group
• Based on the presence or absence of two
major antigens on red blood cell membranes
• Antigen A
• Antigen B
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Antigens and antibodies of the ABO blood group
Blood Type Antigen
Antibody
A
A
Anti B
B
B
Anti A
AB
A and B
Neither Anti A nor Anti B
O
Neither A nor B Both Anti A and Anti B
Genotype of ABO blood groups
Blood Group
Possible Genotype(s)
A
AA, AO
B
BB, BO
AB
AB
O
OO
Landsteiner’s law.
1. If an agglutinogen (antigen) is present on the
RBCs the corresponding agglutinin (anti
body) must be absent in the plasma
2. If an agglutinogen (antigen) is absent on the
RBCs the corresponding agglutinin (anti
body) must be present in the plasma
The first law is applicable to all blood groups. But the second
part is not necessary always, its true for ABO blood groups.
Rh Blood Group
• The Rh blood group was named for the rhesus
monkey
• The group includes several Rh antigens or factors
(Cc, Dd & Ee)
• Rh positive – presence of antigen D or other Rh
antigens on the red blood cell membranes
• Rh negative – lack of these antigens
• The seriousness of the Rh blood group is evident in a
fetus that develops the condition erythroblastosis
fetalis or hemolytic disease of the newborn
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Erythroblstosis Fetalis
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– – –
– – –
– ––
–
–
–
– – –
–
– –
–
–
– – –– – –
– – –
–
– – – –
–
– –
–
+
– –
–
–
+
+
– –
+ + +
–
+
–
+
–
+
– –
–
–
–– –
– – –
– – –
– ––
–
–
–
– – –
–
– –
–
–
– – –– – –
– – –
–
– – ++ +
–
++
–
+
–
+
+
+
– +
+ + +
+
+
–
+
–
+
+
– +
–
–
Rh-negative
woman with
Rh-positive
fetus
Cells from
Rh-positive
fetus enter
woman’s
bloodstream
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– – ––
–
– –
– –
–
–
–
– – ––
– – – –
– – – –– –
–
– ––
– – ––
–
–
– –
– – –
–
–
–
–
–
–
–
– +
–
–
– –
–
–
–
Woman
becomes
sensitized—
antibodies ( + )
form to fight
Rh-positive
blood cells
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– – ––
–
– –
– –
–
–
–
– – ––
– – – –
– – – –– –
–
– ––
– – ––
–
–
– –
– –
–
–
–
–
–
–
–
–
–
–
–
In the next
Rh-positive
pregnancy,
maternal
antibodies
attack fetal red
blood cells
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Erythroblastosis Fetalis
(Hemolytic disease of the newborn-HDN)
• Clinical Features
– Edema (Hydrops)
– Jaundice
– Anemia
– Enlarged Liver & Spleen
Erythroblastosis Fetalis
(Hemolytic disease of the newborn-HDN)
• Treatment
– Exchange blood transfusion
• Prevention
– Rh immune globulin (RhIG) injections to the Rh –
negative mother during pregnancy
Blood groups in local population
Blood Group
Percentage of Population
O+
48 %
A+
24 %
B+
17 %
AB +
4%
Rh Positive are about 93% (90-95%)
O-
4%
A-
2%
B-
1%
AB-
0.23%
Rh negative are about 7% (5-10%)
Blood transfusion
•Autologus blood transfusion
•Blood grouping and cross matching
•Donor’s RBCs + Recipient’s plasma (major
cross matching)
•Recipients RBCs + Donor’s plasma (minor
cross matching)
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Proffered And Permissible Blood Types For
Transfusion
Blood Type
of Recipient
Preferred Blood
Type of The
Donor
Permissible Blood Type of
The Donor (In Extreme
Emergency)
A
A
O
B
B
O
AB
AB
A,B, O
O
O
No alternate type
Complications of Blood Transfusion
• Fatal hemolytic reactions in mismatched
reactions.
• Rapid hemolysis
• Jaundice
• Renal tubular damage
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•
•
•
Circulatory overload – if rapid transfusion
Hemosiderosis – repeated blood transfusion
Electrolyte disturbances
Transmission of disease
• Hepatitis – B or C
• AIDS